A couple of observations on selecting tomatoes: Italians divide them into two classes: insalatari and da salsa. Insalatari, as one might expect, are salad tomatoes, to be eaten raw. People generally select them not-too-ripe, in other words quite firm, with streaks of green running through them, and with a lively acidity that complements the flavor of the greens in the salad. Pomodori da salsa, on the other hand, are for cooking and should be ripe -- an explosive red, rich, and slightly sweet too.
The tomatoes pictured here are Pomodori San Marzano, plum tomatoes from the San Marzano production area on the flanks of Monte Vesuvio. Of course plum tomatoes grow elsewhere too, at which point Italians call them pomodori perini. Pomodori San Marzano/Perini are the classic canning and sauce tomato, and people generally wait until mid-summer, when they're wonderfully sun-ripened, and then buy them in bulk to make tomato sauce for the winter months. They're also nice in other dishes as an ingredient, though they are not so good raw (for example in salad) because they're a bit dry, and firm too.
More Italian Tomatoes:
Tomato Background, Info & Recipes
Pappa al Pomodoro
Pomarola, Tuscan Tomato Sauce
Dino's Marinara Sauce
Spicy Stuffed Plum Tomato Recipe - Perine Piccanti, Spicy Stuffed Plum Tomato Recipe - Perine Piccanti
Tomatoes Elsewhere on About:
Mango Tomato Salsa
Rosemary Beef and Tomatoes
Layered BLT Dip
Turkey Cutlets With Roasted Tomatoes